Ventilation apparatus with integral intumescent fire and smoke stop and method of manufacturing thereof

ABSTRACT

An improved ventilation assembly for preventing fire and smoke from undermining a fire rated surface. The ventilation assembly includes a housing having at least one side wall defining an interior space, and a top wall coupled to the side wall, with an inlet adjacent the at least one side wall and an outlet coupled to the housing. A fluid, such as air, flows between the inlet and the outlet. A fire shielding material is disposed within the interior space, where the fire shielding material expands upon the application of a predetermined amount of heat such that the fire shielding material obstructs the flow of the fluid between the inlet and the outlet.

FIELD OF THE INVENTION

[0001] This invention generally relates to ventilating exhaust fans, such as those typically utilized in bathrooms and other enclosed living spaces. More specifically, the present invention relates to a ventilating apparatus which includes an intumescent fire and smoke stop.

BACKGROUND OF THE INVENTION

[0002] Ventilating exhaust fans, such as those typically included in bathrooms, draw air from within the enclosed area and pass the exhausted air out a vent in the gable or roof of the structure. Ventilation is thus provided for the enclosed living space. Typically, such exhaust fans include a rotating fan wheel having a plurality of vanes that create an outward airflow which, in turn, is directed out of an outlet opening by a curved fan scroll surrounding the fan wheel.

[0003] To meet certain building codes, and to obtain approval from standards organizations, such as Underwriters Laboratories (UL), wall/ceiling exhaust fan designs now utilize a separately installed fire and smoke damper or other mechanical device which allows the exhaust fan to be installed into a fire or smoke rated ceiling or wall. Although such design may meet the codes and standards, they have drawbacks, however, in that this is a very expensive and inefficient way to achieve desired results. For instance, not only does the fan manufacturer have to provide both a specially sized and designed fire or fire and smoke stop to fit any number of fan models, but must also specially design housings which accept the standard fan assembly as well as the fire or fire & smoke stop. In addition, the manufacture and distributor are now required to carry two different Stock Keeping Units (SKU's) for the same fan depending on whether the fan is to be installed into fire rated construction or not. Furthermore, it is expensive to produce a fan enclosure designed to accept current fire stop designs since the fan enclosure has to be significantly larger than a standard fan enclosure. Still further, conventional fire dampers depend upon a trigger mechanism which can fail at a critical time due to fatigue of the springs, relied upon to close the damper, or corrosion of the various parts over time.

[0004] The present invention provides a standard fan housing design that can be economically manufactured and distributed in the field to be installed in both fire or fire and smoke rated ceilings and walls, or non rated walls and ceilings.

[0005] Various other features, objects and advantages of the invention will become apparent from the following description taken together with the drawings.

SUMMARY OF THE INVENTION

[0006] In view of the shortcomings of the prior art, the present invention provides an improved ventilation assembly which obstructs the flow of air, smoke and/or fire through the assembly.

[0007] The ventilation assembly comprises a housing having at least one side wall defining an interior space, and a top wall coupled to the side wall; an inlet adjacent the at least one side wall; an outlet coupled to the housing, a fluid flowing between the inlet and the outlet; and a fire shielding material disposed within the interior space, the fire shielding material expanding upon the application of a predetermined amount of heat such that the fire shielding material obstructs the flow of the fluid between the inlet and the outlet.

[0008] According to another aspect of the invention, the fire shielding material is an intumescent thermoplastic polymer.

[0009] According to still another aspect of the invention, the fire shielding material is coupled to at least one of the side wall and the top wall.

[0010] According to a further aspect of the invention, the assembly further comprising a fan motor assembly disposed within the interior space between the top wall and the inlet.

[0011] According to yet a further aspect of the invention, the fire shielding material is disposed between the fan motor assembly and the inlet.

[0012] According to another aspect of the invention, the fire shielding material is disposed between the fan motor assembly and the outlet.

[0013] According to yet another aspect of the invention, the assembly is mounted in a fire rated surface.

[0014] According to yet another aspect of the invention, a method for selectively allowing and preventing the flow of a fluid through a fire rated surface, comprises the steps of: forming a housing defining an interior space; coupling an inlet adjacent the housing means; coupling an outlet to the housing means, the fluid flowing between the inlet means and the outlet means; and disposing a fire shielding material within the interior space, the fire shielding material expanding upon the application of a predetermined amount of heat to obstruct the flow of the fluid between the inlet and the outlet.

[0015] These and other aspects of the invention are set forth below with reference to the drawings and the description of exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention is best understood from the following detailed description when read in connection with the accompanying drawing. It is emphasized that, according to common practice, the various features of the drawing are not to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. Included in the drawing are the following Figures:

[0017]FIG. 1 is a cut away perspective view of an exemplary embodiment of the present invention;

[0018]FIG. 2A is a side view of the exemplary embodiment of FIG. 1 illustrating the fire stop material in a pre-expanded condition;

[0019]FIG. 2B is a side view of the exemplary embodiment of FIG. 1 illustrating the fire stop material in an expanded condition;

[0020]FIG. 3A is a side view of a second exemplary embodiment of the present invention illustrating the fire stop material in a pre-expanded condition;

[0021]FIG. 3B is a side view of the second exemplary embodiment of the present invention illustrating the fire stop material in an expanded condition;

[0022]FIG. 4A is a side view of a third exemplary embodiment of the present invention illustrating the fire stop material in a pre-expanded condition;

[0023]FIG. 4B is a side view of the third exemplary embodiment of the present invention illustrating the fire stop material in an expanded condition;

[0024]FIG. 5A is a side view of a fourth exemplary embodiment of the present invention illustrating the fire stop material in a pre-expanded condition;

[0025]FIG. 5B is a side view of the fourth exemplary embodiment of the present invention illustrating the fire stop material in an expanded condition; and

[0026]FIG. 6 is a cut away perspective view of another exemplary embodiment of the present invention.

[0027] It should, of course, be understood that the description and drawings herein are merely illustrative and that various modifications and changes can be made in the structures disclosed without departing from the spirit of the invention. Like numerals refer to like parts throughout the several views.

DETAILED DESCRIPTION

[0028] When referring to the embodiments, certain terminology will be utilized for the sake of clarity. Use of such terminology is intended to encompass not only the described embodiment, but also technical equivalents which operate and function in substantially the same way to bring about the same result.

[0029] Referring now more particularly to the drawings and FIG. 1 thereof, a partial cut-away view of a ventilation assembly 100 according to an exemplary embodiment of the present invention is shown. As illustrated, ventilation assembly 100 includes a housing 102 which is formed from side walls 104 and top wall 106. Housing 102 has an interior space 112 defined by side walls 104 and top 106. Top wall 106 may be formed form a separate piece of material from that of side walls 104, or may be formed from a unitary piece of material. Either or both side walls 104 and top wall 106 may be formed from a metal, such a steel, and/or from a polymer, as desired. In its practical application, ventilation assembly 100 is installed in structure 125 (shown in FIG. 2A), such as a wall (horizontal mounting) or a ceiling (vertical mounting).

[0030] Attached to housing 102 is inlet 108, such as a grill assembly formed from a polymer or metal, that allows inlet air 114 to flow though lovers 109 and into interior space 112 of housing 102. Also coupled to housing 102 is outlet 110 from which outlet air 116 passes. Within interior space 112 is motor assembly 120 (shown in FIG. 2A) to move air from the inlet 108 to the outlet 110. Although as shown, outlet 110 has a generally circular cross section, the invention is not so limited, however, in that outlet 110 may have other cross sectional configurations, such as rectangular for example, to accommodate duct work or tubing (not shown) for exhausting outlet air 116 therethrough.

[0031] In this exemplary embodiment, fire shielding material 118 is positioned on the inside surface of top 106. In an exemplary embodiment of the present invention, fire shielding material 118 is an intumescent thermoplastic polymer, and may be provided in the form of sheets or as a liquid, for example. Fire shielding material 118 may be applied to top 106 using conventional means, such as with an adhesive having heat resistant properties or screws, for example, when provided in the form of sheets, or may be applied with a brush or sprayed on, for example, when provided in liquid form. For purposes of illustration, fire shielding material 118 is only partially shown. In the exemplary embodiment, however, fire shielding material 118 will cover a substantial portion of the inside surface of top 106 based on the expansion characteristics of fire shielding material 118.

[0032] Upon the application of a predetermined amount of heat (presumably from a fire), fire shielding material 118 expands within interior space 112 to obstruct the back flow of air into outlet 110 and out of inlet 108 to minimize the supply of air for feeding the fire. In addition, the expansion of fire shielding material 118 obstructs the flow of smoke and flame into interior space 112 and out through outlet 110. In this way, the fire and smoke are not advanced through the fire rated structure (not shown) within which ventilation assembly 100 is installed.

[0033] Referring now to FIG. 2A, a side view of the exemplary embodiment of FIG. 1 is shown. As illustrated, fan assembly 120 (which includes a motor 119 and fan blade 121) is mounted on venturi plate 122 within interior space 112 of ventilation assembly 100. As shown in FIG. 2A, fire shielding material 118 is in an unexpanded (normal) condition. As such, low pressure inlet air 114 flows into inlet 108, through venturi plate 122, into fan blade 121, and is ejected from outlet 110 as high pressure air 116.

[0034] Referring now to FIG. 2B, a side view of the exemplary embodiment of FIG. 1 is shown after the ventilation assembly is exposed to a source of excessive heat (not shown), such as a fire. As illustrated, fire shielding material 118A has expanded within interior space 112 to substantially fill interior space 112. As such, low pressure air 114 (or smoke and/or fire) is blocked by the expansion of fire shielding material 118, as indicated by arrows 115, and is unable to exhaust though outlet 110. In this way the smoke and/or fire are unable to breech the fire rated structure into which ventilation assembly 100 is installed. As is known to those of skill in the art, motor assembly 120 may also include a thermal cut off to disable motor assembly 120 during a fire. It is important to note, however, that the expansion of fire shielding material 118 is not inhibited by the operation of fan assembly 120, and may actually enhance the speed at which fire shielding material 118 expands during a fire event by spreading heat within interior space 112.

[0035]FIG. 3A illustrates a side view of a ventilation assembly 300 according to another exemplary embodiment of the present invention. This exemplary embodiment is similar to the first exemplary embodiment except that motor assembly 120 is mounted to top plate 106 and fire shielding material 318 is disposed on the upper surface of venturi plate 122. As in the first exemplary embodiment, low pressure air 114 enters though inlet 108, through venturi plate 122, into fan blade 121, and is ejected from outlet 110 as high pressure air 116.

[0036]FIG. 3B illustrates a side view of the exemplary embodiment of FIG. 3A after ventilation assembly 300 is exposed to a source of excessive heat. Similar to the first exemplary embodiment, upon the application of excessive heat fire shielding material 318A expands in interior space 112 to obstruct the flow of air, fire and/or smoke between inlet 108 and outlet 110.

[0037]FIG. 4A illustrates a side view of ventilation assembly 400 according to yet another exemplary embodiment of the present invention. This exemplary embodiment is similar to the second exemplary embodiment except that outlet 410 is mounted to top plate 406 rather than to the side wall 404. In addition, fire shielding material 418 may be mounted to either or both of the upper surface of venturi plate 422 and the inside of side wall 404. As in the previous embodiments, low pressure air 114 enters though inlet 108, through venturi plate 422, into fan blade 121, and is ejected from outlet 110 as high pressure air 116.

[0038]FIG. 4B illustrates a side view of the exemplary embodiment of FIG. 4A after ventilation assembly 400 is exposed to a source of excessive heat. Similar to the previous embodiments, upon the application of excessive heat, fire shielding material 418A expands in interior space 412 to obstruct the flow of air, fire and/or smoke between inlet 108 and outlet 410.

[0039]FIG. 5A illustrates a side view of ventilation assembly 500 according to still another exemplary embodiment of the present invention. This exemplary embodiment is similar to the first exemplary embodiment except that outlet 410 is mounted to top plate 406 rather than to the side wall 404. In addition, fire shielding material 418 may be mounted to either or both of the inner surface of top 406 and the inside of side wall 404. As in the previous embodiments, low pressure air 114 enters though inlet 108, through venturi plate 422, into fan blade 121, and is ejected from outlet 410 as high pressure air 116.

[0040]FIG. 5B illustrates a side view of the exemplary embodiment of FIG. 5A after ventilation assembly 500 is exposed to a source of excessive heat. Similar to the previous embodiments, upon the application of excessive heat, fire shielding material 418A expands in interior space 412 to obstruct the flow of air, fire and/or smoke between inlet 108 and outlet 410.

[0041] Referring now to FIG. 6, ventilation assembly 600 is illustrated according to another exemplary embodiment of the present invention. This exemplary embodiment is similar to the previous exemplary embodiments expect that the configuration of housing 602 is generally circular having a substantially contiguous side wall 604. Side wall 604 and top 606 define an interior space 612. As illustrated in FIG. 6, fire shielding material 618 is partially shown disposed on the inside surface of top 606. This embodiment is no so limited, however, in that fire stopping material 618 may be disposed on either the upper surface of venturi plate 622 and/or the inside surface of side wall 604, in addition to or as a substitute for the placement of fire stopping material 606 as shown in FIG. 6.

[0042] Upon the introduction of excessive heat, fire shielding material 618 expands into interior space 618, similar to the previous exemplary embodiments described above, to obstruct the flow of air, smoke and/or fire through interior space 612 and out through outlet 610.

[0043] Although the invention has been described with reference to exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the true spirit and scope of the present invention. 

What is claimed:
 1. A ventilation assembly comprising: a housing having: i) at least one side wall defining an interior space, and ii) a top wall coupled to the side wall; an inlet adjacent the at least one side wall; an outlet coupled to the housing, a fluid flowing between the inlet and the outlet; and a fire shielding material disposed within the interior space, the fire shielding material expanding upon the application of a predetermined amount of heat such that the fire shielding material obstructs the flow of the fluid between the inlet and the outlet.
 2. The ventilation assembly according to claim 1, wherein the fire shielding material is an intumescent thermoplastic polymer.
 3. The ventilation assembly according to claim 1, wherein the fire shielding material is coupled to at least one of the side wall and the top wall.
 4. The ventilation assembly according to claim 3, wherein the fire shielding material is applied to the interior space in the form of a liquid.
 5. The ventilation assembly according to claim 1, wherein the at least one side wall is formed in substantially a circular configuration.
 6. The ventilation assembly according to claim 1, wherein the at least one side wall is a plurality of side walls formed in a substantially rectangular configuration.
 7. The ventilation assembly according to claim 1, further comprising a fan motor assembly disposed within the interior space between the top wall and the inlet.
 8. The ventilation assembly according to claim 7, wherein the fan motor assembly moves the fluid between the inlet and the outlet.
 9. The ventilation assembly according to claim 8, further comprising a thermal cutoff to disable the fan motor assembly at least upon the application of the predetermined amount of heat.
 10. The ventilation assembly according to claim 7, wherein the fire shielding material is disposed between the fan motor assembly and the inlet.
 11. The ventilation assembly according to claim 7, wherein the fire shielding material is disposed between the fan motor assembly and the outlet.
 12. The ventilation assembly according to claim 1, wherein the fluid is air.
 13. The ventilation assembly according to claim 1, wherein the fluid is at least one of smoke and fire.
 14. The ventilation assembly according to claim 1, wherein the assembly is mounted in a fire rated surface.
 15. The ventilation assembly according to claim 14, wherein the fire rated surface has a substantially vertical orientation.
 16. The ventilation assembly according to claim 14, wherein the fire rated surface has a substantially horizontal orientation.
 17. The ventilation assembly according to claim 1, wherein the outlet is disposed in the at least one side wall.
 18. The ventilation assembly according to claim 1, wherein the outlet is disposed in the top wall.
 19. The ventilation assembly according to claim 1, wherein the fire shielding material is mounted with an adhesive.
 20. The ventilation assembly according to claim 1, wherein the inlet and the outlet are substantially perpendicular to one another.
 21. The ventilation assembly according to claim 1, wherein the housing assembly is formed from at least one of a metal and a polymer.
 22. An ventilation assembly comprising: housing means for defining an interior space, and inlet means for permitting the entry of a fluid into the interior space; outlet means for permitting the exit of the fluid from the interior space; and fire shielding means for expanding upon the application of a predetermined amount of heat and obstructing the flow of the fluid between the inlet means and the outlet means.
 23. The ventilation assembly according to claim 22, further comprising circulation means for moving the fluid between the inlet means and outlet means prior to the application of the predetermined amount of heat.
 24. An electric motor according to claim 22, wherein the inlet means and the outlet means are substantially perpendicular to one another.
 25. A method for selectively allowing and preventing the flow of a fluid through a fire rated surface, the method comprising the steps of: forming a housing defining an interior space, and coupling an inlet adjacent the housing means; coupling an outlet to the housing means, the fluid flowing between the inlet means and the outlet means; and disposing a fire shielding material within the interior space, wherein upon the application of a predetermined amount of heat the fire shielding material expands and prevents the flow of the fluid between the inlet and the outlet.
 26. An exhaust fan assembly having a rear cover, a housing defining and interior space and attached to the rear cover in fluid tight relation, an inlet adjacent the housing, and an outlet coupled to one of the rear cover and the housing, the improvement which comprises: a fire shielding material disposed within the interior space, the fire shielding material expanding upon the application of a predetermined amount of heat such that the fire shielding material obstructs a flow of fluid between the inlet and the outlet.
 27. The ventilation assembly according to claim 26, wherein the fluid is at least one of smoke and fire. 